Experimental study on ultrasonic signal transmission within the water-filled pipes

We present the results of system design and experiments carried out in a water tank and water-filled pipes using wireless ultrasonic communication methods. The experimental study by measurement and analysis of multipath ultrasonic transmission within water-filled pipes and its effect on the transmission link are investigated. Pulsed carrier signals of short duration are used to estimate the characteristics of the channels and the results have been used to improve the performance of the ultrasonic transmission link. The link is to be used to control and talk with an ROV named Pipe Rover. The studies show that the transmission in the pipes is, as expected, much more reverberant than in the open water. A digital link has been tested at a bit rate of 600 baud at the transmission level using FSK modulation.